Figure 6.
An example GDF file.
This GDF file has 5 nodes:
me,
friend_1,
friend_2,
friend_3 and
friend_4.
Also, this GDF file has 7 edges.
This GDF file also makes use of the built-in node label and weight columns, in the node and edge sections, respectively.

Two Sections To A GDF File Format

You probably already noticed that a GDF file has 2 section:
a node-section and an edge-section.

If we consider the GDF files in figure 3, the node-section is:

nodedef> name
a
b
c
d
e

Figure 7.Part of the GDF file from figure 3.
This part of the GDF file lists the nodes in the graph.

And the edge-section is:

edgedef> node1,node2
a,b
b,c
b,d
d,e

Figure 8.Part of the GDF file from figure 3.
This part of the GDF file lists the edges in the graph.

If you take what is in figure 7 and figure 8 and combine them (to get what you have in figure 3) you have a complete GDF file.